ETABS Model

FIVE STOREY RCC MULTISTOREYED BUILDING USING ETABS 2015 Data: No. of storeys

:

GF +4

Typical floor height

:

3.0m

Bottom Height

: 2.0m

Length along X axis

: 7.0m (2 Bays Each Bay =3.50m)

Length along Y axis

: 13.50m (3 Bays Each Bay =4.50m)

Column size

: C1 230 x 300 mm (End Column) C2 230 x 380 mm (Side Column) C3 230 x 450 mm (Inner Column)

Beam size

: B1 230 x 380 mm (Short span) B2 230 x 450 mm (Long span)

Slab Thickness

: 125 mm

Concrete Grade

: M25

Steel Grade

: Fe 500

1.Creating Geometry or Model :

Open ETABS from Desktop or from Start Menu The Start up Screen will appear.

Click New Model. OR File menu  New Model. Model Initialisation screen will appear.

Choose  “ Use Built-in Settings With “ option.

Select Metric SI units, Indian Codes as shown above and click OK. New Model Quick Template will appear. In the Grid Dimension Plan

 Uniform Grid Spacing No. of Grid lines in X Direction

: 3

No. of Grid lines in Y Direction

: 4

Spacing of Grids in X Direction

: 3.50m

Spacing of Grids in Y Direction

: 4.50m

Click Grid labels. X Grid beginning ID: 1

Y Grid beginning ID : A Ok.

In Storey Dimensions enter No. of storeys

: 6 (6 Levels 1 for Ground+4 Storeys+ 1 Roof slab)

Typical storey height

: 3.0m

Bottom storey height

: 2.0m

Select Grid Only button  Ok. Model with white background appear on the screen.

Note : If you want to change the background Go to Main menuDisplay Graphical Display  Set display color by changing screen as Block BackgroundOk.

Close Model explorer X button on the left side. Now You can see the block background screen as follows:

Edit menu  Edit Stories & Grid System  Click Modify/Show Storey Data. Storey data screen will appear Make necessary changes for Similar storey option i.e. Roof, Plinth as Master Storey Ok. Ok.

2. Define Material Properties: Define menu Material Properties

Following screen will appear.

Add New Material Ok. Choose the Region as India , Material type as Concrete & Grade as M25. Ok.

Following screen will appear.

Click Ok. Similarly Add New Material Choose the Standard and Material type as Rebar & Grade as HYSD Grade 500 Ok.

Following Screen will appear.

Click Ok Ok. 3. Define Section Properties: Define Beam : Define menu  Section Properties  Frame section.

Following screen will appear.

Click Delete Multiple Properties Select all sections to be deleted Click Delete Selected Frame Sections Ok.

Click Add New Property.

Choose Concrete Rectangular Section  Ok.

Give Property Name as B1 230 x 380 for Beam 1. Choose Material as M25 and give section dimensions Depth : 380 mm Width: 230 mm. Then Click Modify/Show Modifiers and Choose Torsional Constant=0.01 Moment Inertia about 2 axis=0.35 Moment Inertia about 3 axis=0.35 Ok.

Then click Modify/Show Rebar.

Choose Design Type as  M3 Design only (Beam) Rebar Material : Longitudinal bar and Ties as HYSD 500 Give Cover Top & Bottom as =25+8+16/2=40mm Ok. Add New Property  Choose Concrete Rectangular SectionOk. Give Property Name as B2 230 x 450 for Beam 2. Choose Material as M25 and give section dimensions Depth : 450 mm Width: 230 mm. Then Click Modify/ Show Modifiers and Choose Torsional Constant=0.01 Moment Inertia about 2 axis=0.35 Moment Inertia about 3 axis=0.35 Ok. Click Modify/show Rebar  Choose Design Type as  M3 Design only (Beam) Rebar Material : Longitudinal bar and Ties as HYSD 500 Give cover Top & Bottom =25+8+16/2=40.

Ok

Add New Property  Choose Concrete Rectangular SectionOk. Give Property Name as PB 230 x 300 for Plinth Beam. Choose Material as M25 and give section dimensions Depth : 300 mm Width: 230 mm. Click Modify/Show Rebar  Choose Design Type as  M3 Design only (Beam) Rebar Material : Longitudinal bar and Ties as HYSD 500 Give cover Top & Bottom =25+8+16/2=40 Ok. Define Column : Add New Property  Choose Concrete Rectangular Section.

Give Property Name as C1 230 x 300 for Corner Column . Choose Material as M25 and give section dimensions Depth : 300 mm Width: 230 mm. Then Click Modify/ Show Modifiers and Choose Torsional Constant=0.01 Moment Inertia about 2 axis=0.70

Moment Inertia about 3 axis=0.70 Ok.

Click Modify/Show Rebar  Choose  P-M2-M3 Design Column Rebar Material : Longitudinal bar and Ties as HYSD 500. Choose  Rectangular, Ties. Give Cover =40+8+16/2=60. No. of longitudinal bar along 3rd face = 3 No. of Longitudinal bar along 2nd face =3 Longitudinal bar Dia=16mm, Corner bar Dia=16mm Confinement Dia (ties) =8mm Ok

Similarly Add New Property  Choose Concrete Rectangular SectionOk. Give Property Name as C2 230 x 380 for Side Column . Choose Material as M25 and give section dimensions Depth : 380 mm Width: 230 mm. Then Click Show Modifiers and choose Torsional Constant=0.01 Moment Inertia about 2 axis=0.70 Moment Inertia about 3 axis=0.70 Ok. Click Modify/show Rebar  Choose  P-M2-M3 Design Column , Material : Longitudinal bar and Ties as HYSD 500. Choose Rectangular,  Ties. Give cover =40+8+16/2=60. No. of longitudinal bar along 3rd face = 3 No. of Longitudinal bar along 2nd face =3 Longitudinal bar Dia=20mm, Corner bar Dia=20mm Confinement Dia (ties) =8mm Ok. Add New Property  Choose Concrete Rectangular SectionOk. Give Property Name as C3 230 x 450 for Inner Column . Choose Material as M25 and give section dimensions Depth : 450 mm Width: 230 mm. Then Click Modify/Show Modifiers and Choose Torsional Constant=0.01 Moment Inertia about 2 axis=0.70

Moment Inertia about 3 axis=0.70 Ok.

Click Modify/show Rebar  Choose  P-M2-M3 Design Column , Material : Longitudinal bar and Ties as HYSD 500. Choose  Rectangular,  Ties. Give cover =40+8+16/2=60. No. of longitudinal bar along 3rd face = 3

No. of Longitudinal bar along 2nd face =3 Longitudinal bar Dia=20mm, Corner bar Dia=20mm Confinement Dia (ties) =8mm Ok Ok. Define Slab : Define menu  Section Properties Slab section.

Following screen will appear.

Delete the first existing Property. Click Modify/ Show Property Ok.

Choose Slab Property Name as Slab1, Material as M25 , Modeling type as Membrane and Thickness as 125 mmOk Ok.

Note: Some others give Modeling Type as Shell Thin instead Membrane. 4. Drawing the Structure : ( Beams, Columns and Slabs) Note: Make sure Snap to Grid is On, in order to snap to existing grid. For that right Click Choose Snap option  Ok.

Take default screen OR Tick Joints, Line Ends and Mid points, Grid intersections, Perpendicular Projections, Intersections.

Drawing Beam: For the Beam, Beam sizes for Roof to Storey 2 will of same size and Beam for Plinth will be different. Accordingly storey data will be changed. Choose Top Roof Storey. Set Storey Data by going Edit menu  Edit Stories & Grid System  Click Modify/Show Storey Data. Storey data screen will appear Make necessary changes for Similar storey option Ok. Ok.

Main MenuDraw Draw Beam/Column/ Brace objects Draw Beam/ Column/ Brace. OR Quick Draw Beans/Columns.

Choose B1 230 x 380 in Properties window.

Set Similar stories from bottom right of the screen .

Draw the beams B1 by simply clicking on the grid in the left side Plan view. This will draw beams B1 on all floors except plinth level as seen from perspective view on right side window.

Similarly Choose B2 230 x 450 in property window and draw the Beams B2 by simply clicking on the grid in the left Plan view as per plan .

Keep Plinth level on the left side Plan view by pressing Up or Down arrow on top Tool bar. Choose PB 230 x 300 in Properties window and set with One storey option on bottom Right of the screen and select all the Plinth beams plan on left side view.

by windowing the

Drawing Column : The various storeys of the column section is kept same throughout the height. Accordingly Similar Storey option shall be kept as similar to Beam. Keep Storey 5 as Master storey and Storey 4, Storey 3, Storey 2 ,Storey 1 and Plinth as Similar Storey . Set plan view in Roof level. Main MenuDraw Draw Beam/Column/ Brace objects Draw Beam/ Column/ Brace. OR Quick Draw Columns.

Choose C1 230 x 300 in Properties window. Note: In Column if you choose Angle deg as 0º, the Column position will be rectangular horizontal and if angle deg 90º is chosen, column position will be Rectangular vertical.

Change angle as 90◦ for the position of Corner column. By selecting All Stories option button from bottom right of the screen.

Draw columns by clicking Corner Column C1 locations by windowing each column separately. Choose C2 230 x 380 in Properties window and change angle to 90◦ and with All Stories option draw side columns C2 by windowing each column locations separately. Choose C3 230 x 450 in Properties window and with All Stories option draw inner columns C3 by windowing each column locations separately. If necessary change angle to 90◦

Drawing Slab: For the Slab, location for slab is from Roof to Storey 1 only. At Plinth level there is no slab. Accordingly storey data will be changed. Choose Top Roof Storey. Set Storey Data by going Edit menu  Edit Stories & Grid System  Click Modify/Show Storey Data. Storey data screen will appear Make necessary changes for Similar storey option Ok. Ok.

Draw menu  Draw Floor/ Wall objects Quick draw Floor/Wall

Choose S1 in Property window on the left. Click on each Rectangular grid where slabs should come. OR on left side screen Select All tool bar for selecting all portion of slab. Select Similar storeies option button for selecting all floor slabs.

5. Assigning Support Condition : Set Base floor Plan view in left window by pressing Up and Down arrow.

 Select all Column points by windowing with One storey option button. From Assign menu Joint  Restraints .

Select FixedOk.

To see the Support assigned, Click Left plan view and Click Elevation view on top Tool bar. Select Section 1 Ok.

Following screen will appear.

6. Defining Loads : Gravity loads (Dead & Live load) Note: For Self weight multiplier will be 1 for slabs, beams and columns of dead load. For other loads, it will be zero. Dead Load of Beams, Columns and slabs are automatically calculated by ETABS as per Section Properties and Material properties that we have assigned already for dead load calculation. (i) Defining Load Patterns: Define menu Load Patterns.

By Default the screen will show only Dead and Live Load.

If you want to add any other loads like Wind or Earthquake loads, give a name under load and choose type and click Add New Load button. Load=SIDL (Super Imposed Dead Load) Type = Super Dead Self weight Multiplier=0 Add New Load Load = Wall Type =Dead Self weight Multiplier=0 Add New Load Ok.

(ii) Defining Load cases: Define menu Load Cases.

As we have to do Linear Static Accept default screen Click Ok. (iii) Defining Load Combinations: Define menu  Load Combinations.

Click Add New Combination button. Give Name as Comb1.5 . Click Load Name =Dead and Scale Factor=1.5 Add. Select Load Name=SIDL and Scale Factor=1.5  Add. Select Load Name=Wall and Scale Factor=1.5  Add. Select Load Name=Live and Scale Factor=1.5  Ok.

Click Add New Combination button. Give Name as Comb 1. Click Load Name =Dead and Scale Factor=1 Add. Select Load Name=SIDL and Scale Factor=1  Add. Select Load Name=Wall and Scale Factor=1  Add. Select Load Name=Live and Scale Factor=1  Ok Ok.

(iv) Define Mass Sourses: Define menu Mass Sources

Modify/ Show Mass SourcesOk.

Mass Source Name :MsStc1 Mass Source : Specified Load Masses Choose Load Pattern as Dead and Multiple =1.0 Add. Load Pattern =SDL and Multiple =1.0 Add. Load Pattern =WALL and Multiple =1.0 Add. Choose Load pattern as Live and Multiple=0.25 (LL < 3.0KN/m2) Add OkOk. (v) Define Modal Cases : Define menu  Modal Cases

 Click Modify/Show Case  Ok.

Choose Modal Case Name : Modal Modal Case Sub Type Max. No. of Modes

: Eigen : 100

(3 x 4 columns x 7 joints=84 say 100)

OkOk. 7. Assign Loads: (i) Loads on Slab: Loads on Roof Slab: We have to Assign Dead Load, Terrace Weathering Coarse (SIDL) of 2.25KN/m2 and Live load=1.50KN/m2 on Roof slab. Keep Plan view in Roof level. Choose one Storey in bottom right. Set storey data with Roof, Storey5, Plinth as Master Storey.

Select all slabs in Roof.

Assign menu Shell Load Uniform

Load Pattern Name =SIDL Load =2.25 KN/m2

Direction : Gravity

Options : Add to Existing Loads  Apply Ok.

Select menu Get Previous Selection.

Main menu  Assign Shell Load Uniform. Load Pattern Name = Live Load =1.50 KN/m2

Direction : Gravity

Options : Add to Existing Loads  Apply Ok.

Loads on Floor Slab: Keep Storey 5 in Plan view. Choose Similar Storey in bottom right. Select all Floor slab. Assign menu Shell Load Uniform. Give Live Load=2.0 KN/m2

Direction : Gravity Options : Add to Existing Loads  Apply Ok.

In the same manner Go to Select menu  Get Previous Selection. Load Pattern Name = SIDL Load =1.0 KN/m2

(Floor finish)

Direction : Gravity

Options : Add to Existing Loads  Apply Ok.

Wall Loads on beams : Parapet Wall Load= 0.23 x 1 x 20=4.60 KN/m. Keep Roof storey. Choose one storey option in right bottom. Select outer portion of Beam.

Assign menu Frame Loads Distributed.

Select Load Pattern Name : WALL. Load Type=Force. Uniform load=4.60 KN/m Add to Existing Loads Ok.

Wall load on Floor beams: 0.23 x (3.0-0.45) x 20= 12 KN/m (Outer wall) Inner Wall Loads on beams : 0.115 x (3.0-0.45) x 20 =6.0 KN/m Keep storey 5. Choose Similar storey option in right bottom. Select outer portion of Beam.

Assign menu Frame Loads Distributed. Select Load Pattern Name : WALL. Load Type=Force. Uniform load=12.0 KN/m Add to Existing Loads Ok.

In similar manner select inner portion of beam and assign Wall load=6.0KN/m. Add to Existing Loads Ok.

Load on plinth Beam : 0.23 x (3.0-0.45) x 20 =12 KN/m.i Keep Plinth level in plan vew with one Storey option in bottom right. Select entire beam by windowing. Assign menuFrame Loads Distributed. Select Load Pattern Name : WALL. Load Type=Force. Uniform load=12.0 KN/m Add to Existing Loads Ok.

To view Loads: Click on Display Framed Load icon on the tool bar as shown below:

Click Right side window  Select Load Pattern =Wall  ApplyOk.

Similarly you can select Live Load or SIDL and see the Load value on the Right side view. 8. Check the Model: Main menu Analyse Check Model.

Check model have no errors or warning.

Close the screen.

9. Set Diaphragm Select menu Select PropertiesSlab section Select Slab 1Selected Close.

Assign menu Shell  Diaphragms.

Select D1  Ok.

To see the type of Daiphragms:

10. Analysis: Analyse menuSet Load Cases To Run .

Run Now Ok.

After successfully analyzing you will see the deformed shape as default screen.

Click Animation at bottom to see the animation of the structure.

11. Results : 11.1 Deformed Shape: Display menu  Deformed Shape .

Select Load Case Combs and Select Comb 1.5Ok.

d

11.2. To view the Loads acting on the Struxture: Display menu Load Assigns. 11.3 To view BMD & SFD: Display menu Frame / pier/Spandrel/ Link Forces or F8 button or

Select Load case (Case) or Combination (Combo), Moment 3-3 Ok.

icon.

BMD Diagram View set elevation view on left window. Select BMD for the required frame.

To see Shear Force Diagram : Select Shear 2-2 Apply.

Shear Force diagram Frame 1-1 To see Axial Force : Select Axial Force Apply.

Axial Force Diagram

BMD in left side window Right click on any Beam to see the individual beam BMD & SFD as below: Move the mouse on the Shear/ Moment diagram to the value on the particular section.

11.4 To Erase the Results: In order make changes in the Model after run the analysis, you have to erase the results. Display menuUnlock Model.

Click Ok. Then after making necessary changes run the program again. 12. Concrete Design: Design menu Concrete frame Design View / Revise Preferences.

Make Changes if any required Ok.

Design menu  Concrete Frame Design Select Design combinations. Design menu  Concrete Frame Design Start Design /Check.

Note: Before Go to design, Analyse  Run Analysis. After Concrete design start you will see the screen as follows:

The Reinforcement Details of Beam at Top and Bottom will display on the screen.

Set to Elevation view=1 in right window Reinforcement area will be displayed on the Frame.

Right click on any of the member to see the design information.

Click summary button to view the detailed result.

-Summary - Flexural details

- Shear details

- Envelope  Ok.

To see the % of steel on Beams and Columns: Design menuConcrete frame design Display design Information

 Select Design output= Select Rebar percentage Ok.

13. Detailing : Detailing menu  Detailing Preferences (for setting units)

Choose any unit you want to change Ok.

Detailing menu  Concrete Component Preferences Beam. (for setting labels etc)

Accept Default secreen Ok. Similarly for Columns.

Detailing menu  Rebar Selection Rules Beams (for Longitudinal, Stirrups details)

Choose changes if any in the Smallest Bar Dia, Largest Bar Dia, Preferred Bar Dia and Click Ok.

Similarly for Column reinforcement do the same.

Detailing menu Start Detailing (will start detailing the members)

You can see the detailed results for all beams, columns and slabs.